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Biomedical subjects

B Elkin

Publications and source records attributed to B Elkin.

9 recordsLinked to original sources
PubMed2003

Concentrations of selected essential and non-essential elements in arctic fox (Alopex lagopus) and wolverines (Gulo gulo) from the Canadian Arctic.

Arctic fox (Alopex lagopus) and wolverine (Gulo gulo) tissues were collected in the Canadian Arctic from 1998 to 2001 and analyzed for various essential and non-essential elements. Several elements (Ag, Al, As, B, Ba, Be, Co, Cr, Mo, Ni, Sb, Sn, Sr, Tl, U and V) were near or below the detection limits in >95% arctic fox and wolverine samples. Concentrations of Cd, Cu, Fe, total Hg (THg), Mn, Pb, Se and Zn were quantifiable in >50% of the samples analyzed and reported herein. Hepatic elemental concentrations were not significantly different among arctic foxes collected at Ulukhaqtuuq (Holman), NT (n=13) and Arviat, NU (n=50), but were significantly greater than concentrations found in wolverine liver from Kugluktuk (Coppermine), NU (n=12). The mean (+/-1 S.E.) concentrations of Cd in kidney were also significantly greater in arctic fox (1.08+/-0.19 microg g(-1) wet wt.) than wolverine (0.67+/-0.18 microg g(-1) wet wt.). However, mean hepatic Cu concentrations (Ulukhaqtuuq: 5.5+/-0.64; Arviat: 7.1+/-0.49 microg g(-1) wet wt.) in arctic foxes were significantly lower than in wolverines (32+/-3.3 microg g(-1) wet wt.). Hepatic total Hg (THg) concentrations in arctic fox from this study were not significantly different from specimens collected in 1973, suggesting that THg concentrations have not changed dramatically over the past 30 years. The mono-methylmercury (MeHg) concentrations in selected (n=10) arctic fox liver samples from Arviat (0.14+/-0.07 microg g(-1) wet wt.) comprised 14% of THg. While the molar concentrations of THg were correlated with Se in arctic foxes and wolverines, the hepatic Hg/Se molar ratios were consistently lower than unity; suggesting that Se-mediated detoxification pathways of Hg are not overwhelmed at current exposure.

Animals↗
PubMed2003

Profile of persistent chlorinated contaminants, including selected chiral compounds, in wolverine (Gulo gulo) livers from the Canadian Arctic.

Wolverines (Gulo gulo) are circumpolar omnivores that live throughout the alpine and arctic tundra ecosystem. Wolverine livers were collected at Kugluktuk (Coppermine), NU (n=12) in the western Canadian Arctic to report, for the first time, the residue patterns of persistent organochlorine contaminants (OCs) in this species. The enantiomer fractions (EFs) of several chiral OCs, including PCB atropisomers, in wolverines were also determined. Results were compared to OC concentrations and EFs of chiral contaminants in arctic fox (Alopex lagopus) from Ulukhaqtuuq (Holman), NT (n=20); a closely related species that scavenges the marine and terrestrial arctic environment. The rank order of hepatic concentrations for sum ( summation operator ) OC groups in wolverines were polychlorinated biphenyls ( summation operator PCB)>chlordane-related components ( summation operator CHLOR)>DDT-related compounds ( summation operator DDT)>hexachlorocyclohexane isomers ( summation operator HCHs). The most abundant OC analytes detected in wolverine liver were PCB-153, PCB-180, and oxychlordane (OXY). Wolverine age and gender did not influence OC concentrations, which were comparable to lipid-normalized values in arctic fox. The EFs of several chiral OCs (alpha-HCH, cis- and trans-chlordane, OXY, heptachlor exo-epoxide) and PCB atropisomers (PCB-136, 149) were nonracemic in arctic fox and wolverine liver and similar to those previously calculated in arctic fox and polar bears from Iceland and the Canadian Arctic. Results suggest that these species have similar ability to biotransform OCs. As well, contaminant profiles suggest that terrestrial mammals do not represent the major source of OC exposure to wolverines and that wolverines are scavenging more contaminated prey items, such as marine mammals. While summation operator PCB did not exceed the concentrations associated with mammalian reproductive impairment, future research is required to properly evaluate the potential affect of other OCs on the overall health of wolverines.

Animals↗
PubMed2003

Organochlorine contaminant and stable isotope profiles in Arctic fox (Alopex lagopus) from the Alaskan and Canadian Arctic.

Arctic fox (Alopex lagopus) is a circumpolar species distributed across northern Canada and Alaska. Arctic fox muscle and liver were collected at Barrow, AK, USA (n=18), Holman, NT, Canada (n=20), and Arviat, NU, Canada (n=20) to elucidate the feeding ecology of this species and relate these findings to body residue patterns of organochlorine contaminants (OCs). Stable carbon (delta 13C) and nitrogen (delta 15N) isotope analyses of Arctic fox muscle indicated that trophic position (estimated by delta 15N) is positively correlated with increasing delta 13C values, suggesting that Arctic fox with a predominantly marine-based foraging strategy occupy a higher trophic level than individuals mostly feeding from a terrestrial-based carbon source. At all sites, the rank order for OC groups in muscle was polychlorinated biphenyls (Sigma PCB) > chlordane-related compounds (Sigma CHLOR) > hexachlorocyclohexane (Sigma HCH) > total toxaphene (TOX) > or = chlorobenzenes (Sigma ClBz) > DDT-related isomers (Sigma DDT). In liver, Sigma CHLOR was the most abundant OC group, followed by Sigma PCB > TOX > Sigma HCH > Sigma ClBz > Sigma DDT. The most abundant OC analytes detected from Arctic fox muscle and liver were oxychlordane, PCB-153, and PCB-180. The comparison of delta 15N with OC concentrations indicated that relative trophic position might not accurately predict OC bioaccumulation in Arctic fox. The bioaccumulation pattern of OCs in the Arctic fox is similar to the polar bear. While Sigma PCB concentrations were highly variable, concentrations in the Arctic fox were generally below those associated with the toxicological endpoints for adverse effects on mammalian reproduction. Further research is required to properly elucidate the potential health impacts to this species from exposure to OCs.

Alaska↗
PubMed2000

Prevalence of Toxoplasma gondii antibodies in muskox (Ovibos moschatus) sera from northern Canada.

Prevalence of antibodies to Toxoplasma gondii was determined in 203 muskoxen (Ovibos moschatus) from 3 geographically distinct areas of northern Canada (near the hamlets of Kugluktuk and Cambridge Bay, Nunavut and Holman, Northwest Territories) by the modified agglutination test (MAT). Antibodies were found in 13 (6.4%) of 203 animals with MAT titers of 1:25 in 2, 1:50 in 7, 1:200 in 2, 1:400 in 1, and 1:800 in 1. The 4 muskoxen with MAT titers > or =1:200 were adult females and were among 10 animals examined from a mainland population near Kugluktuk. The seroprevalence was lower in Victoria Island muskoxen collected near Cambridge Bay (4.6% of 151) and Holman (4.8% of 42). This is the first serologic survey for T. gondii infection in muskoxen.

Agglutination Tests↗
PubMed1999

Spatial and temporal trends of contaminants in Canadian Arctic freshwater and terrestrial ecosystems: a review.

The state of knowledge of contaminants in Canadian Arctic biota of the freshwater and terrestrial ecosystems has advanced enormously since the publication of the first major reviews by Lockhart et al. and Thomas et al. in The Science of the Total Environment in 1992. The most significant gains are new knowledge of spatial trends of organochlorines and heavy metal contaminants in terrestrial animals, such as caribou and mink, and in waterfowl, where no information was previously available. Spatial trends in freshwater fish have been broadened, especially in the Yukon, where contaminant measurements of, for example, organochlorines were previously non-existent. A review of contaminants data for fish from the Northwest Territories, Yukon and northern Quebec showed mercury as the one contaminant which consistently exceeds guideline limits for subsistence consumption or commercial sale. Lake trout and northern pike in the Canadian Shield lakes of the Northwest Territories and northern Quebec generally had the most elevated levels. Levels of other heavy metals were generally not elevated in fish. Toxaphene was the major organochlorine contaminant in all fish analyzed. The concentrations of organochlorine contaminants in fish appear to be a function not only of trophic level but of other aspects of the lake ecosystem. Among Arctic terrestrial mammals, PCBs and cadmium were the most prominent contaminants in the species analyzed. Relatively high levels (10-60 micrograms g-1) of cadmium were observed in kidney and liver of caribou from the Yukon, the Northwest Territories and northern Quebec, with concentrations in western herds being higher than in those from the east. For the organochlorine contaminants, a west to east increase in zigma PCBs, HCB and zigma HCH was found in caribou, probably as a result of the predominant west to east/north-east atmospheric circulation pattern which delivers these contaminants from industrialized regions of central and eastern North America to the Arctic via long-range atmospheric transport. Radiocesium contamination of lichens and caribou has continued to decrease. Significant contamination by PCBs and lead of soils and vascular plants was observed in the immediate vicinity and within a 20-km radius of DEW line sites in the Canadian Arctic. There was also evidence for transfer of PCBs from plants to lemmings. There was no evidence, however, that large mammals such as caribou living in the general area of the DEW line sites had elevated levels of PCBs. There is very limited temporal trend information for most contaminants in biota of Arctic terrestrial and freshwater environments.

Animals↗
PubMed1997

An evaluation of two primary care interventions for alcohol abuse among Mexican-American patients.

AIMS: This study examined the effects of two primary care interventions (a physician intervention and a clinic-based psychoeducational group) on drinking patterns, psychosocial problems and blood test results (MCV, GGT, SGOT and SGPT). DESIGN: Subjects were randomized into one of four treatment groups: physician intervention, psychoeducation, both interventions, or no intervention. Follow-up data were collected at 12 and 18 months. SETTING: Subjects were recruited from a family practice outpatient clinic managed by a public hospital. PARTICIPANTS: Included 175 Mexican-American female and male primary care patients who screened positive for alcohol abuse or dependence. These patients were not seeking help for alcohol problems. INTERVENTIONS: Included a brief physician intervention and a 6-week patient psychoeducational group. MEASUREMENTS: The Diagnostic Interview Schedule assessed subjects for alcohol abuse; the Addiction Severity Index measured alcohol-related problems, including psychosocial issues. FINDINGS: All four treatment groups demonstrated significant improvement over time, with few differences between intervention and control groups. CONCLUSIONS: Assessment can be confounded with brief interventions; future investigators should use non-assessed control groups.

Adolescent↗
PubMed1991

Observation of a polar bear with rabies.

On 1 November 1989 the first confirmed case of rabies in a polar bear (Ursus maritimus) was encountered by Inuit hunters in the vicinity of Cape Kendall, Southampton Island, Northwest Territories (Canada). The adult male polar bear had posterior paralysis. Rabies was detected by mouse inoculation and a positive immunoperoxidase reaction on spinal cord and Gasserian ganglion from the bear. Histologic lesions in the lumbar region of the spinal cord were consistent with the posterior paralysis. The impact of rabies on the population dynamics of polar bears probably is minimal. Rabies in polar bears constitutes a potential health hazard for polar bear hunters.

Animals↗